A computer where the print screen key isn't workingWhat kind of device are you using?
Pretty much every device allows you to take screenshots, but sometimes it's not obvious how.
Here's a mobile screenshot:
View media item 3070(Text reads "Please can we ensure that we keep on topic about ATO in Thameslink core rather than discussions about people’s apparent wishes for driverless trains which this topic is nothing to do with" in a white box at the top of a user's post)